Billed as one of the biggest astronomical projects of the 21st century, the telescope is located 16,400 feet (5,000 m) above sea level on the side of a mountain overlooking the Atacama Desert.

When work is completed in 2013, the telescope will able to provide unprecedented insights into the origin of the universe by observing cold, molecular gas and radiation left over from the Big Bang.

But with 16 of its planned 66 radio antennas now in place, the ALMA is already able to exceed the capacity of other similar radio telescopes.

“There’s nothing magical about the number 16 but the gain in sensitivity is enormous so it would be a shame not to start performing observations with the ALMA,” Dr. John Richer from the University of Cambridge told BBC World.

The ALMA is the result of a joint project involving participants from Europe, east Asia, North America and Chile.

The telescope’s antennas are 39 feet (12 m) in diameter and their reception systems have been assembled in a variety of countries around the world. Large, 28-wheel trucks fitted with oxygen supplies have been used to transport them to the high altitude site.

Leading international astronomers have rushed to express their interest in using the radio telescope, with more than 1,000 project ideas already submitted to the ALMA team.

Richer said he was not at all surprised by the excitement generated by the new telescope.

“It doesn’t have the same profile as the Large Hadron Particle Collider located in Switzerland, nor its price,” he told BBC World. “But it is the most complex observatory ever constructed on Earth because of its size and the scale of the engineering. We are constructing it because we believe that it will bring incomparable scientific benefits.”